: Short circuits, frayed wires, or poor grounding on the trailer itself are the most frequent culprits.
This often happens after a battery replacement or if a new part was installed without being "re-learned" by the vehicle's computer. ford b166a60
When the Passenger Door Module registers an open circuit, it means the electrical path running from the module to the mirror and back to the ground has broken. The most frequent causes include: : Short circuits, frayed wires, or poor grounding